CVE-2026-6427

Medium

Description

The a3 Lazy Load plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 2.7.6 This is due to a regex bug in the _filter_videos() method that breaks HTML attribute quoting when processing crafted <video> elements, combined with unescaped output in the admin/views/form-data.php template. An authenticated attacker with Contributor-level access can insert a crafted <video> tag whose src attribute contains an embedded class=" substring that tricks the plugin's class-replacement regex into consuming an attribute-value closing quote. This shifts the HTML5 parser's quote boundary, promoting attacker-controlled text from inside a quoted attribute value into standalone event-handler attributes (autofocus, onfocus). The injected script executes in the browser of any user (including administrators) who views the post.

SeverityMedium
CVSS6.4
Exploit probability—
Producta3 Lazy Load
PublishedMay 28, 2026
First seenMay 28, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
a3rev a3 Lazy Loadv ≤ 2.7.6—

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